Their techniques lead to better quality of printed electronic structures while allowing for a wider range of functional inks and ultimately to smaller feature sizes.

Tailoring wettability

Focusing on functional inks for printed electronics, the Fontys team found that tailored wettability is the key to better controlling inkjet processes. For their research they used the PiXDRO LP50 platform and applied the new µPlasmaPrint technology of InnoPhysics, an innovative Dutch high-tech company specializing in patterned plasma treatment equipment.

Plasma treatment of substrates is a well-known method to improve wettability before printing, however, as this is often a treatment of the complete surface, inkjet printed droplets will spread in all directions, creating broader lines. The µPlasmaPrint technology is able to locally change surfaces from hydrophilic to hydrophobic and vice-versa, creating patterns that make droplets spread in only one direction while restraining them in the other direction. Printed lines created in this way have both a very high homogeneity and a well-controlled width.

Perfect match between substrate and printing process

Fontys inkjet printing expert Martijn van Dongen explains: ”In our research we aim to prepare the substrate to match perfectly with the inkjet printing process. For example, in our current study we prepared the substrate with a pure nitrogen plasma to make it hydrophilic and subsequently deposited narrow hydrophobic lines using a plasma with a nitrogen and hexamethyl-disiloxane precursor. With our PiXDRO LP50 printing platform, which integrates both the µPlasmaPrint head and several different inkjet heads, we were then able to print exactly between the two hydrophobic lines. The versatility of the platform permits us to explore the combination of different plasma treatments, precursors, printing heads and functional inks that we believe will help industry in manufacturing printed electronics.”
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More information: Innophysics